The invention relates to a driving system for miniature dictating machines with winding drive, comprising a rewinding shaft and a forward winding shaft for receiving tape windings, and a motor with its drive shaft arranged in a plane substantially perpendicular to the rewinding and forward winding shafts.
Such driving systems for miniature dictating machines must be as compact as possible thereby defining the outer dimensions of the miniature dictating machine. On the other hand, the efficiency of the driving systems of miniature dictating machines must be as high as possible, i.e., the transmission losses must be as small as possible to achieve by the available energy source, e.g. a battery of limited capacity, a performance as long as possible. Furthermore, the starting torques for the different modes of operation of such miniature dictating machines, e.g. slow and fast forward run and fast rewind must be as small as possible to achieve a drive with compact energy sources and motors as small as possible. Furthermore, an easy operation and change-over to the different modes of operation must be possible.
A driving unit is known wherein the motor is arranged in the miniature dictating machine in such a manner that the motor shaft is disposed perpendicularly to the rewind and forward wind shafts. In said known unit a pivotably mounted intermediate shaft arranged substantially parallel to the motor shaft is driven by a driving belt, which intermediate shaft is provided at either end with driven wheels. When the intermediate shaft is moved into a first position, the first drive wheel drives a driving wheel secured e.g. to the forward winding shaft. When the intermediate shaft is moved into its second position the second drive wheel drives a driving wheel secured to the rewind shaft and thus drives the rewind shaft. The first drive wheel is then in an idle position in which the forward winding shaft is out of action. Disadvantages of this arrangement are especially seen therein that the driving wheel on the intermediate shaft extending perpendicularly and between forward winding shaft and rewind shaft makes the apparatus relatively thick substantially due to the addition of the thickness of the tape cartridge and diameter of the driving wheel.